This was drawn with a 8b Faber Castell pencil, and the eyes were inked in with a Copic marker. I usually have two pencils, one with a sharpened tip, the other shaped with a craft knife  so that about half an inch of lead is usable to shade in with.

This enables me to work fluently.

I also use Blue Tac to lift off lead here and there as highlights. You can shape the Blue Tac to a fine point, or more broader, to suit your needs, and your not using it as a traditional eraser your lifting the lead, or charcoal, etc off the page, instead off rubbing it out.